H-Bridge Configuration for Wide Range Speed Control of DC Motor

Majority of the industrial drives are AC drives, due to their robust construction, low power loss, low maintenance and simple starting arrangement. However, these motors are constant speed drives and do not allow smooth speed control over a wide range and operation in either direction. Direct current (DC) motor has already become an important drive configuration for many applications across a wide range of powers and speeds. The ease of control and excellent performance of the DC motors will ensure that the number of applications using them will continue grow for the foreseeable future. To operate motor in either direction DC motor can be used because of its simplicity. Although conventional methods are available for speed control, modern high speed switching power devices have opened new area in this field. The major advantages of power electronic control of drives are compactness, flexibility and greater precision in speed control. A simple, cost effective and efficient method of controlling the speed of DC motor is to incorporate PWM control. Use of microcontroller reduces the control hardware, increases the reliability and brings in flexibility to the control scheme. To study the efficiency of such systems, in the present work it is planned to design and test PWM controlled H- Bridge Converter for DC motor. The design of converter, generation of PWM pulses and microcontroller programs developed in the present work are discussed in detail in this report.